The ING New York City Marathon on November 4 will mark Meb Keflezighi’s 10th anniversary of running 26.2-mile races. His 17th marathon will also be his fourth in 12 months.

Yet the natural question is not whether he is at the end of his rope for the year or for his career. The question is, can he run another personal best, at the age 37?

Why not? He’s run two PBs in the past year, in addition to finishing fourth at the London Olympics in August. At an age when most world-class marathoners have retired, Keflezighi keeps running faster.

“It’s the ultimate test for the body to do four marathons in one year,” said Keflezighi, the 2009 ING New York City Marathon champ and the 2004 Olympic silver medalist in the marathon. “Another PR in New York would be a huge story. Especially at 37.”

Keflezighi, who has six top-10 finishes in seven New York City marathons, ran a personal best of 2:09:13 in New York last year for sixth place while still a young pup of 36. He was disappointed, however, feeling that he was ready for a 2:07 or better. But he had blister problems courtesy of leaving a Breathe Right nasal strip in his shoe–and stomach problems requiring two pit stops.

In January he won the U.S. Olympic Marathon Trials in Houston in another PR, 2:09:08, even though he was able to run on just 48 of the intervening 70 days between marathons because of complications from the blister. “That showed how good shape I was in for New York,” he said.

He will have 84 days between his fourth-place finish in London and the 43rd edition of New York. In the Olympic marathon he was as far back as 19th in the first half of the race before steadily passing competitors in the second half. Bob Larsen, who has evolved from coach to mentor/friend in his 19 years of coaching Keflezighi, thought it was one of the runner’s most courageous performances.

Because of hip flexor and glute problems, plus illness, Keflezighi’s training was far from ideal. “I just ran out of [training] time,” he said.

He’s recovering nicely from the August 12 marathon in London, now that his feet are feeling better after taking a beating on cobblestones and gravel, which required him to use a wheelchair at Heathrow when he was leaving for home.

“For me the goal is to get to the starting line healthy,” Keflezighi said. “If I can stay healthy and put in decent training, I usually come around pretty fast.”

Keflezighi may be the James Brown of his event: The hardest-working man in the marathon business. His dedication to training and recovery are major reasons he’s still running so well. He estimates that he has run more than 60,000 miles in his career, much of it at his altitude base in Mammoth Lakes, CA. His training days start early with the first of what is usually two daily runs.

“Then it’s nonstop ’til I put my head on the pillow at about 10:00 p.m.,” said Keflezighi. “Three hundred and sixty-five days a year, I’m trying to do everything right.”

There are weight training, stretching, form drills, massage, chiropractic adjustments, and dreaded ice baths, some in mountain streams. He has paid more attention to nutrition in recent years, battling vitamin D and calcium deficiencies.

He salutes his team, which includes Larsen; his wife, Yordanos; their three young girls; and his agent/brother, Merhawi Keflezighi: “My team has been outstanding and the support from my sponsors has been outstanding, allowing me to do what I do best.”

The Keflezighi work ethic is legendary for those who know that the family, who emigrated from Eritrea to Italy to San Diego, arriving in 1987 with no knowledge of English and just the clothes on their backs. Now all 11 children, including a doctor, a lawyer, an engineer, and the owner of an MBA, have either graduated or are attending California universities.

“To be born in Eritrea and come out of that situation, Yordanos and I and our family have to pinch ourselves all the time,” Keflezighi says. “This is the American dream.”

As much as he loves running and as well as he has performed recently, Keflezighi, under contract to run the ING New York City Marathon in both 2012 and 2013, knows that his world-class days are coming to a close.

“If I’m healthy, I still love the sport and enjoy it,” he said. “When I have a setback, it’s tough. I contemplate whether to hang it up or not. Other than that, I love being fit. My sponsors pay me to be fit. Everybody else in world would like that job. I have the best job in the world.”

Dick Patrick is co-author with Meb Keflezighi of the marathoner’s autobiography, “Run to Overcome.”